The mystery begins in a St. Louis, Mo., field on June 30, 1999. Ricky McCormick, 41, was found dead in a field, and his killer hasn't been caught.

That's where you come in. The FBI said two encrypted notes were found in the victim's pants, and their code crackers haven't been able to figure out what the notes mean.

"We are really good at what we do," said Dan Olson, the chief of the FBI's Cryptanalysis and Racketeering Records Unit. "But we could use some help with this one."

"Breaking this code could reveal the victim's whereabouts before his death and could lead to the solution of a homicide," Olson said. "Not every cipher we get arrives at our door under those circumstances."

Here are the codes:

?Even if we found out that he was writing a grocery list or a love letter, we would still want to see how the code is solved. This is a cipher system we know nothing about," Olson said.

If you have an idea how to break the code, or you have seen similar codes, contact the FBI: